Take a look at the sentence again:
Waves that crash against the shore,
chanting monks, and
chirping birds are the sound files Wendell
enjoys on his iPod.
When you list grammatical items, you must use parallel structure. Here, chanting monks and chirping birds are both noun phrases, but waves that crash against the shore is a noun modified with an adjective clause, which wrecks the parallelism.
To fix the sentence, change waves that crash against the shore to crashing waves.